I've made my first "perfect server - without ISPConfig" with the help of the tutorials can be find at How To Forge. So I am very new at server configuration.
My mail server built up with postfix, amavisd-new, SpamAssassin, ClamAV + MySQL, and running on Debian Lenny.

Everything works fine but I always get "Considered UNSOLICITED BULK EMAIL, apparently from you" message in my outlook: